Presentation on theme: "Lab Two, Part 2: Blood and MSA, pg 429 Lab Two, Part 1: Coagulase Test, pg 429 Exp 29: Catalase Test Physical Factors Exp 15: Temperature Exp 16: pH Exp."— Presentation transcript:
Lab Two, Part 2: Blood and MSA, pg 429 Lab Two, Part 1: Coagulase Test, pg 429 Exp 29: Catalase Test Physical Factors Exp 15: Temperature Exp 16: pH Exp 17/18: O 2 Requirements Week 10W Exp 62: ID of Human Staph. and Strep. Pathogens Lab Two, pg 196 add H 2 O 2 Last week: New This Week: Gram (+) Bacteria ID Review Gram + and - tests New This Week: Gram (+) Bacteria ID Review Gram + and - tests Gram staining practice
Exp 62: ID of Human Staph. And Strep. Pathogens: Blood and MSA Review An MSA plate with Micrococcus sp. (1), Staphylococcus epidermis (2) and S. aureus (3) colonies.MicrococcusStaphylococcus epidermis S. aureus Red blood cells on an agar plate are used to diagnose infection. On the left is a positive Staphylococcus infection, on the right a positive Streptococcus pyogenes culture. Red blood cellsinfection StaphylococcusStreptococcus
Exp 62: ID of Human Staph. And Strep. Pathogens: Coagulase Test Coagulase reacts with the fibrinogen in plasma, and precipitates into fibrin cells clump together, look lumpy. Test useful for differentiating Staphylococcus aureus from other Gram positive, catalase + cocci. Any degree of clotting, from a loose clot suspended in the plasma to a solid, immovable clot is a positive result. Plasma which liquid remained is a negative result.
Exp 62: ID of Human Staph. And Strep. Pathogens: Coagulase Test fibrin
Exp. 29: Catalase Test o Hydrogen peroxide (H 2 O 2 ) accumulation is toxic to cells. o Presence of bubbling or foaming when adding H 2 O 2 to a culture, indicates that the hydrogen peroxide is being broken down by catalase, with the release of oxygen gas. o Bubbling = pos. catalase o Absence of foaming/bubbling= neg. catalase (catalase is not present in cell)
Results To ID Gram Positive Bacteria Notation MICROORGANISM Staph. epidermidis (SE) Staph. aureus (SA) B. subtilis (BS) Strep. salivarius (SS) M. luteus (ML) Morphology shape/ arrangement cocci/ cluster rodscocci/ chaincocci/ cluster TSA (cultural characteristics) color, size, form, margin, elevation, texture +/- growth MSA MF or NMF/ color Blood Agar (cultural characteristics) color, size, form, margin, elevation, texture Blood Hemolysis У α β Catalase Activity +/- catalase Coagulase Actvity +/- coagulase
Seafloor bacteria on ocean-bottom rocks are more abundant and diverse than previously thought. Grand Prismatic Spring, Yellowstone National Park (thermophiles) Below Freezing Salt Water Pockets in Antarctica Bacteria Around Nuclear Reactors Biofilm build-up on tank walls guaranteed to contaminate any fuel
Exp 15: Physical Factors: Temperature
Exp 16: Physical Factors: pH of the Extracellular Environment
Exp 17/18: Physical Factors: Atmospheric Oxygen Requirements CategoryOxygen RequirementProduction of Catalase Obligate Aerobe Requires oxygen and oxygen is not toxic to it.Produces catalase. MicroaerophileRequires oxygen at low levels and atmospheric levels of oxygen are toxic to it. Prefers oxygen at a concentration lower than 10%. Produces catalase sometimes. Facultative Anaerobe Uses oxygen preferentially when oxygen is present, but can grow without oxygen (slower growth than with oxygen). Oxygen is not toxic to it. Produces catalase. Obligate anaerobe Does not use oxygen and oxygen is toxic to it.No catalase production. AerotolerantDoes not use oxygen, but oxygen is not toxic to it. Produces catalase. How is distribution of growth affected by atmospheric oxygen ……..?
TABLES 5 & 6 Exp. 17/18: Atmospheric Oxygen Requirements Media: 3Thioglycollate broth 3 NUT broth Culture: EC, ML & CS Procedure: (refer to pg. 127) Label ea. tube w/org & media. Inoculate each org. in thioglycollate and NUT broth. Place thioglycollate tubes in anaerobic GasPack chamber. Incubate all at 37 o C for 24 hrs. Week 10W GLU SUC LAC TABLES 1 & 2 Exp 15: Temperature Media: 12 NUT slant Culture: SA, ML, BST Procedure: (refer to pg. 111) Label each tube w/ org. and temp. Inoculate with loop 4 slants w/each org. Incubate 1 slant from each org. at either 4 o C, 25 o C, 37 o C, and 55 o C for 24 hrs. TABLES 3 & 4 Exp 16: pH of the Extracellular Environ. Media: 2 NUT pH 2 2 NUT pH 5 2 NUT pH 7 2 NUT pH 9 Culture: EC & SA Procedure: (refer to pg. 116) Label each tube w/ org. and pH. Inoculate with ea. org in various pH tubes. Incubate at 37 o C for 24 hrs. BST- Bacillus stearothermophilus CS- Clostridium sporogenes Gram staining practice